The recent popularity of the 110 format camera and disc camera require that color prints obtained by enlarging a small-disc image have graininess and a degree of resolution comparable to those using a large-sized image.
Two methods of improving graininess are described in T. H. James, ed., The Theory of the Photographic Process, page 621 (4th ed., 1977, MacMillan). One of the procedures increases the number of developing sites in silver halide grains and further controls the amount of a dye formed. The other procedure makes a dye cloud formed by color development indefinite. Increasing the number of silver halide grains while maintaining a given photographic sensitivity is accompanied by an increase in the amount of silver to be coated and thus by a deterioration in the degree of resolution. The first procedure, therefore, is disadvantageous from the viewpoints of production costs and photographic performance. An attempt to improve graininess through diffusion of a dye uses a dye diffusible type coupler, as described in Japanese Patent Application (OPI) No. 82837/82 (the term "OPI" as used herein means a "published unexamined Japanese patent application"). In this procedure, however, the color print is visually unsatisfactory, as will be described later in detail, although the RMS (root mean square) graininess is improved.
As a result of investigations to improve graininess, it has been found that if a non-diffusible type coupler capable of producing a dye of such mobility that controlled image smearing occurs on reacting with an oxidation product of a developing agent (which is hereinafter referred to as "smearing dye-producing coupler") is used to improve graininess, the RMS graininess (which is described at page 619 of the above-described James reference) is greatly improved. In this case, however, since the arrangement of silver halide grains and development probability occur in varied steps, the dye diffuses and then intermingles with an adjacent dye. This increases the overlapping of dye clouds, resulting in the formation of gigantic dye clouds at random. The formation of such gigantic dye clouds is visually very unpleasant, and in some cases, the color print looks as if the graininess were deteriorated.